This example encodes a minimalist grid in the style of Sol LeWitt, using a 50 × 50 set of horizontal and vertical rectangles. The rectangles are masked by two overlapping circular threshold patterns, effectively revealing a cross-hatched composition that changes with the mask geometry. The implementation uses D3’s `select`, `range`, and `symbol` APIs to build SVG elements and path masks, with the `symbol` function generating a large circular clip path via `symbols[1]`. The rendered output is entirely vector-based, with masks defined through SVG `mask` elements and applied to both sets of rectangles.